Add Collection.flatMapDeep function

pierredup · pierredup · commit be7ca0afc1da · 2018-03-26T08:58:13.000+02:00
diff --git a/src/Collection/flatMapDeep.php b/src/Collection/flatMapDeep.php
@@ -0,0 +1,39 @@
+<?php
+
+declare(strict_types=1);
+
+/*
+ * This file is part of the SolidWorx Lodash-PHP project.
+ *
+ * @author     Pierre du Plessis <open-source@solidworx.co>
+ * @copyright  Copyright (c) 2017
+ */
+
+namespace _;
+
+use function _\internal\baseFlatten;
+
+/**
+ * This method is like `flatMap` except that it recursively flattens the
+ * mapped results.
+ *
+ * @category Collection
+ *
+ * @param iterable collection The collection to iterate over.
+ * @param callable $iteratee The function invoked per iteration.
+ *
+ * @return array Returns the new flattened array.
+ * @example
+ * <code>
+ * function duplicate($n) {
+ *   return [[[$n, $n]]];
+ * }
+ *
+ * flatMapDeep([1, 2], 'duplicate');
+ * // => [1, 1, 2, 2]
+ * </code>
+ */
+function flatMapDeep(iterable $collection, callable $iteratee = null): array
+{
+    return baseFlatten(map($collection, $iteratee), \PHP_INT_MAX);
+}
diff --git a/tests/Collection/FlatMapDeepTest.php b/tests/Collection/FlatMapDeepTest.php
@@ -0,0 +1,25 @@
+<?php
+
+declare(strict_types=1);
+
+/*
+ * This file is part of the SolidWorx Lodash-PHP project.
+ *
+ * @author     Pierre du Plessis <open-source@solidworx.co>
+ * @copyright  Copyright (c) 2017
+ */
+
+use PHPUnit\Framework\TestCase;
+use function _\flatMapDeep;
+
+class FlatMapDeepTest extends TestCase
+{
+    public function testFlatMapDeep()
+    {
+        $duplicate = function ($n) {
+            return [[[$n, $n]]];
+        };
+
+        $this->assertSame([1, 1, 2, 2], flatMapDeep([1, 2], $duplicate));
+    }
+}
